Multilayered Clouds Identification and Retrieval for CERES Using MODIS

Traditionally, analyses of satellite data have been limited to interpreting the radiances in terms of single-layer clouds resulting in large errors in the retrieved properties for multilayered cloud systems. Several new techniques have been developed to detect multilayered clouds and to estimate the properties of those clouds classified as multilayered, using multispectral techniques that combine imager data with secondary imager products. These include the infrared brightness temperature differences, BTD and microwave radiance (MWR) data. The BTD method is limited to optically thin cirrus over low clouds, while the MWR methods are generally limited to ocean areas. This paper explores the use of the BTD and MWR methods as applied to Moderate Resolution Imaging Spectroradiometer (MODIS) and Advanced Microwave Scanning Radiometer EOS (AMSR-E) data taken from the Aqua satellite. The detection and cloud property retrieval techniques for multilayered clouds are described. Cloud radar and lidar data from surface sites are used to validate the results. The identification of multilayered cloud pixels will aid in further improvements in deriving surface, atmosphere, and Top-of-atmosphere radiation budgets using the Clouds and Earth's Radiant Energy System (CERES) data.